Cylinder head number 1.0 French engine

[Barry james]

Hi, on the front of a 1.0 French Yaris 1999 - 2005 engine there is a U number stamped on the front of the cylinder head , does anybody know what that stands for or is it better performance to get on with a higher U value like for example U6 or U7? Thanks Barry james

[bathtub tom]

Up, as in this way up?

[flash22]

It's a casting number, pre mid 2001 they are Jap built, 2002 there was a big change in engine management and sensors

heads are all the same, a few changes in cam spec but nothing major, it's fuel injected no mods will increase power unless you map the ecu

want to go faster - tires, brakes and suspension are the first port of call